shwild.Rust

SHell-compatible WILDcards, for Rust — part of the cross-language shwild family.

Introduction
- Pattern Elements
Installation
Components
- Constants
- Enumerations
- Features
- Functions
- Macros
- Structures
- Traits
Examples
Project Information

Introduction

shwild is a small, standalone library, implemented in C++ with a C and a C++ API, that provides shell-compatible wildcard matching. shwild.Rust is a Rust port, with minimal API differences. The design emphasis is on simplicity-of-use, modularity, and performance.

	let pattern = r"Where are the* [🐼🐻]s\?";

	assert_eq!(Ok(false), shwild_matches!(pattern, ""));
	assert_eq!(Ok(false), shwild_matches!(pattern, "Where are the bears?"));
	assert_eq!(Ok(true),  shwild_matches!(pattern, "Where are the 🐻s?"));
	assert_eq!(Ok(true),  shwild_matches!(pattern, "Where are the 🐼s?"));
	assert_eq!(Ok(true),  shwild_matches!(pattern, "Where are their 🐻s?"));
	assert_eq!(Ok(true),  shwild_matches!(pattern, "Where are the big brown 🐻s?"));
	assert_eq!(Ok(false), shwild_matches!(pattern, "Where are the teddy-🐻s?"));

(See Examples section for more examples.)

Pattern Elements

The library (and other shwild variants) support the following pattern elements:

Literal - a non-empty string fragment, as in "Where are the", which matches the exact same string fragment in the input;
Wild-1 - represented by the single character '?' in the pattern, which represents a match of exactly any one character. In the above example r"Where are the* [🐼🐻]s\?" the '?' is not interpreted as a wild-1 because it is escaped by the '\' character and instead part of the literal fragment "s?";
Wild-N - represented by the single character '*' in the pattern, which represents a match of any number of characters;
Range - represented by a sequence of characters within '[' and ']', as in the "[🐼🐻]" fragment in the above example, which will match to any one of range character in the input. As well as an unordered sequence of literal characters, ranges may also capture contiguous sequences, as in "[zc-aja]" (any of characters 'a', 'b', 'c', 'j', 'z') or in "[abm-PrZ]" (any of characters 'a', 'b', 'm', 'M', 'n', 'N', 'o', 'O', 'p', 'P', 'r', 'Z');
Not-range - represented in the same form as a Range but where the first range character is '^' and the remaining characters represent a set of characters that cannot appear (at the requisite position) in the input;

Installation

Reference in Cargo.toml in the usual way:

shwild = { version = "0.2" }

Components

Constants

The constant IGNORE_CASE causes matching to ignore case.

Enumerations

The shwild::Error enum is used to represent a parse result, defined as:

pub enum Error {
    /// Parse error encountered.
    ParseError {
        line :    usize,
        column :  usize,
        message : String,
    },
}

The shwild::Result enum is a specialized std::result::Result type for shwild, defined as:

pub type Result<T> = std_result::Result<T, shwild::Error>;

Features

The following crate features are defined:

Name	Effect	Is `"default"`?
`"assertions"`	Provides `assert_shwild_matches!()` and `assert_shwild_not_matches!()` test assertion macros (via base-traits `AsI64`)	Yes
`"lookup-ranges"`	Causes match/non-match ranges to be implemented in terms of `UnicodePointMap` (from collect-rs crate), resulting in significant performance improvements in parsing and matching	Yes
`"null-feature"`	A feature that has no effect (and, thus, is useful for simplifying driver scripts)	No
`"test-regex"`	Introduces a dependency to regex crate to support benchmark/example program(s)	No

Functions

The shwild::matches() function attempts to parse a pattern according to flags and then match against it the string input.

pub mod shwild {

	pub fn matches(
		pattern : &str,
		input : &str,
		flags : i64,
	) -> Result<bool>;
}

Macros

The shwild::shwild_matches!() macro is a shorthand for the shwild::matches() function, providing 2-parameter and 3-parameter forms. The 2-parameter form passes 0 for the flags parameter.

The shwild::assert_shwild_matches!() and shwild::assert_shwild_not_matches!() macros are test-oriented counterparts that panic on failure. Each provides 2-parameter and 3-parameter forms; the 2-parameter form passes 0 for the flags parameter. A parse error in the pattern panics with a descriptive message rather than returning Err. They are provided only when the feature "assertions" is enabled, which it is by default.

	use shwild::{
		assert_shwild_matches,
		assert_shwild_not_matches,
		IGNORE_CASE,
	};

	assert_shwild_matches!("[a-d]", "b");
	assert_shwild_not_matches!("[a-d]", "e");
	assert_shwild_matches!("[a-d]", "B", IGNORE_CASE);

Structures

The shwild::CompiledMatcher structure is the data structure that is used to parse the pattern and then test the input string. Because there is a small, but non-zero, cost to parsing patterns - and complex patterns more so, of course - so if matching is to be repeated in a context where performance costs matter then you may prefer to create an instance of CompiledMatcher and then use it to test against, as in:

	let pattern = r"Where are the* [🐼🐻]s\?";

	let flags = 0;
	let matcher = shwild::CompiledMatcher::from_pattern_and_flags(pattern, flags).unwrap();

	assert!(!matcher.matches(""));
	assert!(!matcher.matches("Where are the bears?"));
	assert!( matcher.matches("Where are the 🐻s?"));
	assert!( matcher.matches("Where are the 🐼s?"));
	assert!( matcher.matches("Where are their 🐻s?"));
	assert!( matcher.matches("Where are the big brown 🐻s?"));
	assert!(!matcher.matches("Where are the teddy-🐻s?"));

If you are ever need to get an understanding about the parsed state you can use the Debug implementation for the CompiledMatcher, as in:


	// a pattern for rudimentary Windows path names
	let pattern = r"[A-Z]\?*\?*.[ce][ox][em]";

	let matcher = shwild::CompiledMatcher::from_pattern_and_flags(pattern, flags).unwrap();

	eprintln!("matcher={matcher:?}");

Traits

No public traits are defined at this time.

Examples

Examples are provided in the examples directory, along with a markdown description for each. A detailed list TOC of them is provided in EXAMPLES.md.

Project Information

Where to get help

GitHub Page

Contribution guidelines

Defect reports, feature requests, and pull requests are welcome on https://github.com/synesissoftware/shwild.Rust.

Dependencies

shwild.Rust has three optional dependencies:

base-traits - required if feature "assertions" is specified; supports the flags parameter type in assert_shwild_matches!() and assert_shwild_not_matches!() via AsI64;
collect-rs - required if feature "lookup-ranges" is specified, for more efficient range matching;
regex - required, by some benchmark/example programs only, if feature "test-regex" is specified;

shwild 0.2.0